[media] s5p-mfc: Adjust the default values of some encoder params

The patch sets the default values of MAX_QP and GOP size encoder
parameters to some firmware recommended default values. This enables
the applications to get a better encoded output using the default
settings itself.

Signed-off-by: Kiran AVND <avnd.kiran@samsung.com>
Signed-off-by: Arun Kumar K <arun.kk@samsung.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>